August 2005

1

M9999-082605-B

MIC39500/39501

MIC39500/39501

5A µCap Low-Voltage Low-Dropout Regulator

General Description

The MIC39500 and MIC39501 are 5A low-dropout linear

voltage regulators that provide a low-voltage, high-current

output with a minimum of external components. Utilizing

Micrel’s proprietary Super βeta PNP™ pass element, the

MIC39500/1 offers extremely low dropout (typically 400mV

at 5A) and low ground current (typically 70mA at 5A).

The MIC39500/1 is ideal for PC Add-In cards that need to

convert from standard 2.5V or 3.3V, down to new, lower

core voltages. A guaranteed maximum dropout voltage of

500mV over all operating conditions allows the MIC39500/1

to provide 2.5V from a supply as low as 3V or 1.8V from

2.5V. The MIC39500/1 also has fast transient response, for

heavy switching applications. The device requires only 47µF

of output capacitance to maintain stability and achieve fast

transient response

The MIC39500/1 is fully protected with overcurrent limiting,

thermal shutdown, reversed-battery protection, reversed-

lead insertion protection, and reversed-leakage protection.

The MIC39501 offers a TTL-logic-compatible enable pin and

an error flag that indicates undervoltage and overcurrent

conditions. Offered in a fixed voltages, 1.8V and 2.5V, the

MIC39500/1 comes in the TO-220 and TO-263 packages

and an ideal upgrade to older, NPN-based linear voltage

regulators.

For applications requiring input voltage

greater than 16V, see the

MIC29500/1/2/3 family. For applications

with input voltage 6V or below, see

MIC3750x LDOs.

Typical Application

IN

OUT

GND

3.3V

2.5V

1.0µF

47µF

MIC39500-2.5

MIC39500

Features

• 5A minimum guaranteed output current

• 400mV dropout voltage

Ideal for 3.0V to 2.5V conversion

Ideal for 2.5V to 1.8V conversion

• 1% initial accuracy

• Low ground current

• Current limiting and thermal shutdown

• Reversed-battery and reversed-lead insertion protection

• Reversed-leakage protection

• Fast transient response

• TO-263 and TO-220 packages

• TTL/CMOS compatible enable pin (MIC39501 only)

• Error flag output (MIC39501 only)

• Ceramic capacitor stable (See Application Information)

Applications

• Low Voltage Digital ICs

• LDO linear regulator for PC add-in cards

• High-efficiency linear power supplies

• SMPS post regulator

• Multimedia and PC processor supplies

• Low-voltage microcontrollers

• StrongARM™ processor supply

StrongARM is a trademark of Advanced RISC Machines, Ltd.

MIC39501-2.5

FLG

OUT

ERROR

FLAG OUTPUT

47µF

EN

GND

IN

2.5V

1.0µF

Enable

Shutdown

3.3V

100KΩ

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com